This invention relates to jewelry and more particularly to thermally responsive jewelry that expands and contracts in response to ambient temperatures and body heat to aid in the comfort of wearing the jewelry.
The human body to some degree expands and contracts in response to the ambient temperature as for example, wrist and fingers. Consequently, jewelry that fitted correctly and comfortably when bought at a store may not fit correctly or as well in different thermal environments. Thus, during a hot summer day body appendages tend to swell or enlarge for various biological and thermally related reasons and a finger ring or bracelet not so expanding may pinch, become uncomfortable, or even be impossible to remove.
Conversely, during a cold winter day or in sharp, dry wind, exposed portions of the body tend to contract and in like manner jewelry not so responding would fit loosely, slide distractingly around the wrist or finger and may even slip off.
It is well known that metals generally expand and contract in response to temperature changes. Specific metals expand and contract to greater or lesser extent depending on their composition. This principle has been employed in the fabrication of diverse temperature control and thermostat units. Such units commonly employ bimetallic elements whose physical expansion or contractions effect mechanical movement of a pointer or like member indicating the temperature or to actuate heating and air conditioning equipment as by moving switch elements to open or closed positions.
The commonly used bimetallic unit in a thermometer or thermostat consists of a curved composite strip of metal having a relatively high expansion side and a relatively low expansion side. The two sides constitute strips of bonded metal having differing coefficients of thermal expansion. As the temperature rises and falls, the strips tend to curl or unroll in a predictable and uniform fashion.